Study is pretty accurate from what I can tell
I live in DFW (closest LTE to me is the North most section of the map). This study mirrors what I have seen in practice, as the area I live is on Sprint's LTE map, but not available based on the map from this study. My EVO 4G LTE has only seen 4G signals in some of the areas this study notes are live. Last I heard is that DFW won't be closer to done until at least Feb 2013, and I think that is still optimistic. I really wish Sprint wouldn't have said a market is live for LTE without being at least 50% done. I'm not unhappy with my phone, but there are lots of folks on Sprint's user forums who got phones specifically for LTE service that was coming soon, only to find out "soon" may be closer to a year.
I'm not far from you, yet Sprint has LTE over here I've heard. I'm surprised they don't have LTE coverage in Wylie, yet my VZW phone does...